Fundamentals of Systems Engineering
Prof. Olivier L. de Weck
Session 4 System Architecture
Concept Generation
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Reminder: A2 is due today !
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3
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Overview
System Architecture Definition, Themes, Exercise
NASA Approach
Logical Decomposition
Methods/Tools for Concept Generation
Creativity Techniques
Brainstorming
Morphological Matrix / Architecture Enumeration
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Questions to be asked
Why are we doing the project? Stakeholder Analysis
What must we achieve Requirements Definition
How could we do it? today ! Oftentimes there are many different ways
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Themes: Ambiguity-Creativity-Complexity
C D I O
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Mission concept prelim. detailed chunks integration life-cycle evolution
Complexity
Creativity
Ambiguity
Early on ambiguity is high reduce ambiguity requirements
Next concept are needed focus creativity concepts
Then complexity starts increasing manage complexity designs
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A Definition
Architecture The embodiment of concept, and the allocation of
physical/informational function (process) to elements of form (objects) and definition of structural interfaces among the objects
Consists of: Function Related by Concept To Form
Form
Fu
nc
tio
n
Concept
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Architecture – Civil
Contemporary Beach
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Architecture - Informational
System Boundary
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Architecting Sequence
Reverse
Engineering
Mapping
Form
definition
Function
definition
Mapping
Conceptual
design
In design, you know the functions you want and try to create the form to deliver the function(s)
In reverse engineering, you know the form, and are trying to infer the function (and presumably eventually the goals) 10
Sequences in Design and Reverse Engineering
In Architecting and Design
Define externally delivered function, create
concept, break down functions (“functional
decomposition”), define subsystems
In Reverse Engineering
Define subsystems, infer function, infer concept, infer
externally delivered function (or lack thereof)
Last two steps are difficult due to the emergence of
function
Famous case of reverse engineering: Acutan Zero
http://en.wikipedia.org/wiki/Akutan_Zero
Mitsubishi Zero Fighter (WWII)
This image is in the public domain.
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http://en.wikipedia.org/wiki/Akutan_Zero
Concept
Is created by the architect
Must allow for execution of all functions
Establishes the solution vocabulary
Implicitly represents a technology
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A product or system vision, idea, notion or
mental image which:
Maps Form to Function
Embodies “Working Principles”
Is in the solution-specific vocabulary - it is
the solution
Is an abstraction of form
Is not a product/system attribute, but a mapping
Form
Fu
nc
tio
n
Concept
Concept – Informal Definition
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Expressing Concept
• New Concepts are expressed by a few words or a short phrase (e.g.
refrigerator = insulated box containing mechanically chilled air)
• Established concepts can often be expressed by a word or two
(sometimes the common name of the form associated with the
concept) or an icon
• Once concept is specified, the nature and list of parts is more or less
established
• Concepts, like form, are expressed as nouns, but concepts tend to
be more abstract, while form is actually implemented
• What is the key concept of some of the products we see in this
room?
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Concept - Formal Definition
The specialization of function and mapping to its
physical embodiment of form
The specification of the list of the design variables,
which when specified will define the design
Products based on the same concept are
“continuously connected”
Typically products in a family are based on same concept
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Concept: Gasoline-Electric Hybrid Vehicle
Credit: Dr. Carlos Gorbea, TU Munich
Schematic showing Form
functions
form
form-function-mapping
Multi-domain-matrix
(MDM) showing form and
function
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Partner Exercise (2 min) Pick one of these three objects and describe the concept, using the
language of system architecture
A B
C
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Refrigerator Case Study
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Value - A Formal Definition
Value is delivered when the primary external process(es) acts on the operand in such a way that the needs of the beneficiary are satisfied.
Delivering Primary Process
Operand
Goals
Has
Beneficiary
Needs
Product Object
Interpreting &
Incorporating
Value Delivery
Value Identification
Value Proposition
Using Object-Process-Methodology (OPM) Nomenclature [Dori, 2002] 19
Reduce Ambiguity: Goal Identification Start by examining the operand
associated with value
Next identify the attribute of the operand whose change is associated with value
Next define the transformation of the attribute associated with value, in solution neutral form
This will reduce ambiguity and lead you to a value
focused, solution neutral statement of intent on process
Note: For “Production Systems” the value could be found not in an operand whose attributes are affected but in a resultee that is created
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Focus Creativity : Concept
Concept: a system vision, which embodies working principles, a mapping from function to form
Choose from among the system operating processes that specialize to the desired solution neutral, value related process
Specialize the related generic concept to the product form
This is the
exercise of
creativity
Concept
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Managing Complexity: Decomposition of Function and Form
Identify form of the whole product system
Zoom the processes of function
Decompose the form of the product object
Establish the object process links
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Form and Function -Cooler The whole product includes the ice,
food, supporting surface, heat load, light and operator
Chilling zooms to the stated processes (using process precedence framework)
Cooler decomposes to box and top
Map objects to processes to determine object-process architecture
Establishing the complexity of the object-process architecture
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Design vs. Architecture
• Architecture selects the
concept, decomposition and
mapping of form to function
• Architecture establishes the
vector of design variables and
operating parameters
• Design selects of the values of
the vector of parameters
• This is what optimization is good for
• Some work in “architecture” is
just an exhaustive search over
the design of one architecture
Operating Parameters
Design Variables
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Form and Function - Refrigerator More one to one
correspondence of objects and processes
Note the whole product elements suppressed: Food
Support structure
Heat load
Operator
Simple Object-Process Architecture
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Structure of Form - Refrigerator
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Concept Generation:
Find systems that
do the right thing
Concept Selection:
Find systems that
do the right thing
AND do it well,
i.e. deliver value,
AND comply with
current and future
regulations and
standards
Concept Generation versus Selection
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Systems Architecture - Summary
Architecture requires consideration of form and function, related through concept
Starting with the operand, its transformation identifies concepts which deliver value and meet requirements
Concepts elaborate into architectures which have form-function and structural complexity
“Goodness” of an architecture is a multiobjective value-delivering quality that includes performance, resource utilization, cost, operability and capacity among others
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Overview
System Architecture Definition, Themes, Exercise
NASA Approach
Logical Decomposition
Methods/Tools for Concept Generation
Creativity Techniques
Brainstorming
Morphological Matrix
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NASA SE Handbook: Logical Decomposition Process
3
• Requirement 17 (Section 3.2.3.1) “The Center Directors or designees
shall establish and maintain a process, to include activities,
requirements, guidelines, and documentation, for logical
decomposition of the validated technical requirements of the applicable WBS.”
Logical Decomposition
3
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Logical Decomposition Purpose The Logical Decomposition Process is used to: Improve understanding of the defined technical requirements and the
relationships among the requirements (e.g. functional, behavioral, and temporal)
Transform the defined set of technical requirements into a set of logical decomposition models and their associated set of derived technical requirements for input into the Design Solution Definition Process
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ARCHITECT THE SYSTEM
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Interrelationships Among the System Design Processes
SP-2007-6105, Figure 4.01
3
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Timing Diagram State Diagrams
Example of Decomposition Models 3
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Logical Decomposition Best Practice Process Flow Diagram
Activities Input Output
3
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Overview
System Architecture Definition, Themes, Exercise
NASA Approach
Logical Decomposition
Methods/Tools for Concept Generation
Creativity Techniques
Brainstorming
Morphological Matrix / Architecture Enumeration
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© Olivier de Weck 2015
Creativity Mind Map
C REATIVITY Models
Leonardo da Vinci
Albert Einstein
Thomas Edison
Group
Dynamics
Brainstorming
PowWows
MindBoggling Workouts
Six Hats
de Bono
Structured Processes
STOP
Stimulants
TRIZ MindMapping Morphological
Matrix – Architecture
Enumeration
!
Creativity
in SA
Bio-inspired design
“motion”
random inputs
Challenges
Provocations
alcohol
environment
drugs
3 themes:
creativity, ambiguity
complexity Types of
innovation
high
leverage
F. L. Wright
Fuller
Fukuzawa
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Mind Map
Courtesy of Hayley Davison Reynolds. Used with permission.
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Brainstorming
• Why is brainstorming useful ?
• How to organize and host a brainstorming session ?
• Killer sentences
• What to do with the results ?
• Creativity technique designed to find new ideas as a TEAM
• Lower or remove creativity barriers
• Increase idea production via mutual stimulation
• Ideal group size is 5-10 people with diverse backgrounds
• Use of intuition and association
• Based on a solution-neutral question such as:
“What can be done to …. ?”, “How could we improve … ?”
Attributed to A.F. Osborn
Osborn, A.F., “Applied Imagination. Principles and procedures of creative thinking”, Rev. Ed., New York, 1957
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Organizing a Brainstorming Session
(1) Send out an invitation a few days ahead of time.
Announce brainstorming topic. The brainstorming
is the ONLY agenda item.
(2) Ideally 5-10 (7+/- 2) participants. Facilitator welcomes
participants and briefly describes problem or topic.
(3) Participants take turns expressing thoughts, suggestions,
ideas without the constraints of a particular order.
It is allowed to extend or combine ideas of
others leading to mutual stimulation.
(4) Facilitator takes notes, visible for everyone (e.g. flipchart)
without associating names.
(5) Principle of delayed judgement. No one is allowed to criticize
or particularly praise other ideas. Avoid killer phrases.
(6) Produce a large amount and diversity of ideas. Session ends
after 30-60 minutes or so. Post-Processing happens separately.
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Creativity Killer Sentences
This will never work !
We don’t even need to talk about this !
There’s no time for this !
Why change it … it’s working just fine !
Everyone does it this way !
Who the hell is going to pay for all this ?
You can’t view it this way !
What is YOUR expertise in this field ?
Have you had any previous experience with this ?
You can’t possibly be serious ?
You are completely missing the point !
I have already studied this problem for years !
Do you know where I went to school ?
Don’t worry… I know I’m right.
How long have you been with this company ?
I know what it means to….
Now that we agree on this, let’s move on ...
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Leonardo da Vinci
How to Think Like Leonardo Da Vinci:
Seven Steps to Genius by Michael J. Gelb
“Models” approach to creativity:
Identify exceptionally creative
individuals and ask:
“what principles did they follow ?”
“ where did they find inspiration ? “
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Seven Da Vincian Principles
Curiosita - a lifelong quest for learning
Dimostrazione - testing knowledge through experience
Sensazione - continual refinement of the senses
Sfumato - mastering ambiguity, paradox, and uncertainty
Arte/Scienza - “whole brain” thinking
Corporalita the balance of body and mind
Connessione - the appreciation of patterns, relationships, connections, systems
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Morphological Matrix The simplest structured way to generate different concepts / architectures
List the m key decisions or factors as rows
In each row determine the number of possible alternatives ni
Enumerate all possible combinations N
Example
For many factors, may generate many infeasible architectures
How to prevent that?
Alternatives 1 2 3
Factor A
Factor B
Factor C
The concept shown above is: A2-B1-C3
In total the above matrix can generate N=27 architectures
N = nii=
m
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1
• Systems can be described as sets of components or subsystems connected together to form architectures.
• Designers use creativity, previous experience and analysis to compose components/subsystems into architectures which meet functional
requirements.
Rule Based Architecture Enumeration
Express creativity, previous experience and analysis via rules and components
Rules constrain which components can exist/coexist
Rules constrain which connections can exist/coexist
Creativity
Expert
Knowledge
Analysis
Components
Component Rules
Connection Rules
Architecture Enumeration: Overview
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Architecture Enumeration: Abstraction Layers
Abstraction Layers: Formal Division of design into different layers of
fidelity and subsystem aggregation
1) Intellectually manageable number of components and
connections
2) Minimize the computational resources required to run each
level
Abstraction Layer 0 Tail
Abstraction Layer 1 Tail Architectures
Tail
(Aircraft Design: A Conceptual Approach, Raymer)
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Core
Inta
ke
Pro
pe
ller
Core Nozzle
Co
mp
resso
rs
Burner
Turb
ine
s
Abstraction Layer 1 Engine Core
Abstraction Layer 0 Turboprop
Abstraction Layer Example: Turboprop Core
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Architecture Enumeration Tool
240 Potential Designs Excel Macro based tool from Dr. L. Zeidner at UTRC
Components
Rules
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Lecture Summary System Architecture is the most abstract, but also the most
influential activity in Systems Engineering Concept = Mapping Function to Form Down ~2-levels of abstraction, not all the details
NASA SE Approach focuses on “Logical Decomposition”
Concept Generation is a creative activity Group Dynamics: e.g. Brainstorming Models: e.g. Leonardo da Vinci Structured Processes: MindMaps, Morphological Matrix, Architecture
Enumeration
In Assignment A3 you will generate concepts for 2016 Cansat using at least two different creativity methods of your choice.
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